1. Field
Example embodiments relate to substrate structures, semiconductor devices fabricated from the same, and/or methods of fabricating the semiconductor devices.
2. Description of the Related Art
A gallium nitride (GaN)-based semiconductor may have excellent material properties, such as a large energy gap, high thermal and chemical stability, high electron saturation speed (˜3×107 cm/sec), etc. Furthermore, an electronic device employing a GaN-based semiconductor may have a high breakdown electric field (˜3×106 V/cm), a high maximum current density, stable operation characteristics at high temperatures, a high thermal conductivity, etc. Due to such material properties, a GaN-based semiconductor may be applied to optical devices, high frequency and high power electronic device and a power device.
In fabricating a vertical type device by using a GaN-based nitride semiconductor, a GaN bulk wafer may be used. However, it may be difficult to fabricate a GaN bulk wafer having a large area (that is, a large diameter), and a GaN bulk wafer may be more expensive than other non-GAN substrate materials.